Grinding-machine



(No Model.) J H CRANE 2 Sheets-Sheet 2.

GRINDING MACHINE.

No. 491,530. Patented Feb. 14, 1893.

Um'rnn STATES PATENT Orrrcn.

JOHN II. CRANE, OF AUBURN, NEYV YORK.

GRINDING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 491,530, dated February14, 1893.

Application filed April 22, 1892. Serial No. 430,229- (No model.)

To all whom it may concern.-

Be it known that I, JOHN H. CRANE, a citizen of the United States ofAmerica, residing at Auburn, in the county of Cayuga and State of NewYork, have invented certain new and useful Improvements inGrinding-Machines, of which the following is a specification, referencebeing had therein to the accompanying drawings.

The invention relates to machines for grinding axes, hoes andother'tools having irregular surfaces to be ground, and consists incertain improvements in the construction of such machines as hereinafterdescribed and claimed.

In the accompanying drawings-Figure 1 represents a front'view of themachine. Fig. 2 is a sectional side view of the same. Fig. 3 is a planView. Figs. 4 and 5 illustrate two guide plates employed. Fig. 6illustrates the rack bars and ratchet mechanism. Fig. 7 illustrates inside view the tool-holder and its connections.

A designates the main supporting standards which are connected by a barBat the top and a bar B at the bottomsaid standards being provided withthe longitudinal slots C. To the standards A are rigidly secured thebrackets E by which two guide plates D, D, are supported, being fastenedthereto.

F indicates a traveling column which has a lateral movement between thestandards A, and also a vertical movement by means of a lifter G,connected with said column. To the lower end of the column F is secureda stock or hearing piece H for a shaft I which extends through saidbearing piece and has a crankform a on its lower end, said shaft beingin avertical position. A tool-holderJ is pivoted at c to the bearingpiece H, and is also connected with the crank 11 at W, so that amovement of the tool-holder on its pivot c is imparted from the shaft I,through the crank a, as hereinafter stated. The arms on are removablysecured to the sides of the holder J by screw bolt and nut, the freeends of said arms being turned inward to enter the eye of a tool to beground, and said tool may be secured firmly by said arms to the forwardpart of the tool-holder in position to be ground. The shaft I extendsupward and carries a head-block K which is secured to the upper end ofsaid shaft .and moves between the guide-plates D D. The said head-blockis provided with rollers e for bearing against the inner faces of theopposite plates D D during operation.

L indicates a screw-shaft which is passed through a threaded aperture inthe column F and extends through blocks b which slide in the slots C ofthe standards A. On each end of the shaft L is loosely mounted a pinionM, and a ratchet wheel N is fast on said shaft, a pawl 01 beingconnected with pinion M to con nect with ratchet N. Two shafts 0, onebeing at either side of the shaft L, are passed through the column Fwith their ends extending into the blocks 1) and form guides or ways onwhich the column moves laterally as hereinafter set forth.

I? indicates a shaft mounted in the standards A near the top of themachine; and on said shaft, at its extremities, are the shiftingrack-bars R, which are constructed to engage alternately with pinions M.When one of the rack-bars R is turned down to connect witha pinion M,the other rack-bar is turned from engagement with the opposite pinionand is brought to a horizontal position, such movements of the rack-barsbeing produced by the turning of the shaft P one quarter of arevolution. This turning of the shaft P is effected by the action of thetripping devicesf which are pivoted to the lifter G and severallyimpinge against the cams g which are fast on the shaft P. The springs hserve to hold the rack-bars in position when the latter are turned up,but allow the movements of said bars.

As before stated, the head-block K, being secured to the shaft I, movesbetween the guides plates D D. These two plates are formed with innersurfaces which are somewhat irregular, the plate, D having an innersurface which is somewhat concave and the plate D having a surface thatis correspondingly bulging or convex, so that the head block, duringoperation moving between these surfaces, makes a curving movement andimparts a like movement, through the crankform on shaft I, to thetool-holder J and to the ax or other tool carried by said holder, as thetool bears against the grind stone located in front of the machine. Thecolumn F being drawn upward by means of the lifter G, one of the pinionsM is engaged by one of the rack-bars R, and, through a ratchet and pawl,the screw-shaft is rotated, thus giving the column a lateral movement onsaid shaft; the shaft I, bearing piece H and tool-holder J, makingthesame lateral movement with the column F, the head-block K is movedlaterally between the bulging and convex surfaces of the guide plates Dand D, so that the head-block is somewhat tilted in its movement, and,being fast on the shaft, produces a slight turning movement of thelatter, whereby, through the crank a a turning movement of thetool-holder on its pivot is effected. As the column rises, a trippingdevice f strikes a cam g on the shaft P and partially rotates saidshaft, thus moving the rack R out of engagement and turning the oppositerack into en gagementwith the opposite pinion M 5 as the column Fdescends, its movement on the screw-shaft is reversed and the movementof the head-block between the guide-plates D D is correspondinglyreversed, the tool making a like movement against the face of thegrindstone, according to the action of the crank-form on the lower endof the shaft 1. A press-rod S serves to hold the tool to the grindstone.

1 claim- 1. The combination, with two slotted standards, of two guideplates supported-by said standards, a screw-shaft provided with guidesand a column, movable on said screw-shaft,a vertical shaft mounted inabearing carried by said column and provided with a crank, a pivotedtool-holder attached to said crank, a head-block secured to saidvertical shaft, in position to move between said guide-plates,acam-shaft mounted in said standards, pivoted tripping devices, andrack-bars secured to said cam-shaft and constructed to connectalternately with gearing on said screw-shaft, substantially as set forthand described.

2. In a grinding machine, the combination with a supporting frame, of ascrew-shaft L, having movable bearings, a column mounted on said screwshaft, a vertical shaft I carried by said column, a head block, providedwith rollers, and connected with shaft I, a crank form and tool holderconnected therewith, two guide plates, provided each with a curvedinnersurface, and mechanism for raising said column and for rotating saidscrew-shaft, substantially as set forth and described.

In testimony whereof I have affixed my signature in presence of twowitnesses.

JOHN H. CRANE.

\Vitnesses:

J AMES THOMAS, C. L. I-IIcKoK.

